It is proposed to develop a small, pocket size personal monitor for glutaraldehyde based on the use of a Surface Acoustic Wave (SAW) chemical microsensor as the detector. SAW microsensors are attractive for this application as they are very sensitive to toxic chemicals of modest to low vapor pressure and can be made very selective by the choice of coating applied to the device surface. The SAW devices respond in seconds to exposure to a vapor challenge. SAW sensors can be conveniently used as dosimeters, provided the selected coating interacts irreversibly with the toxic vapor (e.g., glutaraldehyde). Hydrazines, such as dinitrophenyl hydrazine, will be investigated as the active coatings for glutaraldehyde detection. Because of their solid state construction and compatibility with integrated electronics, they have many advantages over currently available personal monitors for toxic vapors. They have the potential to be very small, rugged, low cost, and easily manufactured detection systems. Once the basic personal monitor has been developed, its capability can be readily extended to other toxic vapors simply by the design and selection of suitable interactive coatings for those vapors.